Faculty Bibliography

Basal forebrain cholinergic neuron (BFCN) degeneration is a hallmark of Down syndrome (DS) and Alzheimer's disease (AD). Current therapeutics have been unsuccessful in slowing disease progression, likely due to complex pathological interactions and dysregulated pathways that are poorly understood. The Ts65Dn trisomic mouse model recapitulates both cognitive and morphological deficits of DS and AD, including BFCN degeneration. We utilized Ts65Dn mice to understand mechanisms underlying BFCN degeneration to identify novel targets for therapeutic intervention. We performed high-throughput, single population RNA sequencing (RNA-seq) to interrogate transcriptomic changes within medial septal nucleus (MSN) BFCNs, using laser capture microdissection to individually isolate ~500 choline acetyltransferase-immunopositive neurons in Ts65Dn and normal disomic (2N) mice at 6 months of age (MO). Ts65Dn mice had unique MSN BFCN transcriptomic profiles at ~6 MO clearly differentiating them from 2N mice. Leveraging Ingenuity Pathway Analysis and KEGG analysis, we linked differentially expressed gene (DEG) changes within MSN BFCNs to several canonical pathways and aberrant physiological functions. The dysregulated transcriptomic profile of trisomic BFCNs provides key information underscoring selective vulnerability within the septohippocampal circuit. We propose both expected and novel therapeutic targets for DS and AD, including specific DEGs within cholinergic, glutamatergic, GABAergic, and neurotrophin pathways, as well as select targets for repairing oxidative phosphorylation status in neurons. We demonstrate and validate this interrogative quantitative bioinformatic analysis of a key dysregulated neuronal population linking single population transcript changes to an established pathological hallmark associated with cognitive decline for therapeutic development in human DS and AD.

Respiratory failure is associated with increased mortality in COVID-19 patients. There are no validated lower airway biomarkers to predict clinical outcome. We investigated whether bacterial respiratory infections were associated with poor clinical outcome of COVID-19 in a prospective, observational cohort of 589 critically ill adults, all of whom required mechanical ventilation. For a subset of 142 patients who underwent bronchoscopy, we quantified SARS-CoV-2 viral load, analysed the lower respiratory tract microbiome using metagenomics and metatranscriptomics and profiled the host immune response. Acquisition of a hospital-acquired respiratory pathogen was not associated with fatal outcome. Poor clinical outcome was associated with lower airway enrichment with an oral commensal (Mycoplasma salivarium). Increased SARS-CoV-2 abundance, low anti-SARS-CoV-2 antibody response and a distinct host transcriptome profile of the lower airways were most predictive of mortality. Our data provide evidence that secondary respiratory infections do not drive mortality in COVID-19 and clinical management strategies should prioritize reducing viral replication and maximizing host responses to SARS-CoV-2.

The efficacy of COVID-19 mRNA vaccines is high, but breakthrough infections still occur. We compared the SARS-CoV-2 genomes of 76 breakthrough cases after full vaccination with BNT162b2 (Pfizer/BioNTech), mRNA-1273 (Moderna), or JNJ-78436735 (Janssen) to unvaccinated controls (February-April 2021) in metropolitan New York, including their phylogenetic relationship, distribution of variants, and full spike mutation profiles. The median age of patients in the study was 48 years; 7 required hospitalization and 1 died. Most breakthrough infections (57/76) occurred with B.1.1.7 (Alpha) or B.1.526 (Iota). Among the 7 hospitalized cases, 4 were infected with B.1.1.7, including 1 death. Both unmatched and matched statistical analyses considering age, sex, vaccine type, and study month as covariates supported the null hypothesis of equal variant distributions between vaccinated and unvaccinated in χ2 and McNemar tests (P > 0.1), highlighting a high vaccine efficacy against B.1.1.7 and B.1.526. There was no clear association among breakthroughs between type of vaccine received and variant. In the vaccinated group, spike mutations in the N-terminal domain and receptor-binding domain that have been associated with immune evasion were overrepresented. The evolving dynamic of SARS-CoV-2 variants requires broad genomic analyses of breakthrough infections to provide real-life information on immune escape mediated by circulating variants and their spike mutations.

Background/Purpose: Psoriasis (PsO) is an inflammatory, immune-mediated skin disorder affecting ~3% of the population worldwide. It is associated with multiple comorbidities, including psoriatic arthritis (PsA), which occurs in up to a third of patients. While genes contribute to the pathogenesis of psoriatic disease, twin studies demonstrate substantial discordance in PsO and PsA, suggesting that epigenetics and environmental factors play a significant role. In fact, there is increasing evidence that the microbiome has an impact on psoriatic disease pathogenesis. However, prior investigations were performed in populations of unrelated individuals and could not discern environmental from genetic influences. To characterize the host-microbiome relationship, we studied the gut and skin microbiome of monozygotic (MZ) twins discordant for psoriatic disease in order to determine disease-specific microbial perturbations that are independent of host-genes.
Method(s): Stool and skin swabs were collected from subjects with psoriatic disease and their unaffected MZ twin siblings (pairs=9, n=18). Non-lesional (NL) or healthy skin was swabbed at three separate sites: bicep, scalp, and elbow/forearm. Fecal samples underwent shotgun metagenomic sequencing to deeply characterize the gut microbiome taxonomy and functional pathways at high resolution. Sequences were processed with the HUMAnN and MetaPhlAn2 pipelines. Skin swab samples underwent 16S rRNA sequencing to characterize the cutaneous bacterial microbiome. Forward sequences were processed with the QIIME2 pipeline and SILVA reference database. Downstream computational analysis was performed using several libraries in R, including DESeq2.
Result(s): In gut samples, the relative abundance of Ruminococcus bromii species was significantly reduced and two pathways related to tetrahydrofolate biosynthesis were upregulated in psoriatic twins compared to their corresponding unaffected siblings (Fig 1; p< 0.05, Mann-Whitney). In NL skin samples from psoriatic twins, there was a significant reduction in alpha diversity and beta diversity differences in microbial communities of the scalp, but not the bicep or elbow/forearm, compared to healthy samples from unaffected twins (Fig 2A-B; p< 0.05, Mann-Whitney and Permanova). Differential analysis of taxa in the scalp identified a higher abundance of the Bacillales order and related taxa, as well as a lower abundance of the Deinococcus genus and related taxa in psoriatic twins compared to their unaffected siblings (Fig 2C; p< 0.05 with FDR correction).
Conclusion(s): This is the first study exploring microbial differences in MZ twins discordant for psoriatic disease. In agreement with our previous results, we found that Ruminococcus is reduced or virtually absent in the gut of psoriatic patients, and may therefore be associated with psoriatic disease. Additionally, we discovered that even healthyappearing NL skin of psoriatic subjects, particularly in the scalp, exhibited microbial perturbations and decreased diversity compared to unaffected twins. A further understanding of these changes and their downstream effects should shed light into the pathogenesis of psoriatic disease beyond genetic susceptibility

During the first phase of the COVID-19 epidemic, New York City rapidly became the epicenter of the pandemic in the United States. While molecular phylogenetic analyses have previously highlighted multiple introductions and a period of cryptic community transmission within New York City, little is known about the circulation of SARS-CoV-2 within and among its boroughs. We here perform phylogeographic investigations to gain insights into the circulation of viral lineages during the first months of the New York City outbreak. Our analyses describe the dispersal dynamics of viral lineages at the state and city levels, illustrating that peripheral samples likely correspond to distinct dispersal events originating from the main metropolitan city areas. In line with the high prevalence recorded in this area, our results highlight the relatively important role of the borough of Queens as a transmission hub associated with higher local circulation and dispersal of viral lineages toward the surrounding boroughs.

Mortality among patients with COVID-19 and respiratory failure is high and there are no known lower airway biomarkers that predict clinical outcome. We investigated whether bacterial respiratory infections and viral load were associated with poor clinical outcome and host immune tone. We obtained bacterial and fungal culture data from 589 critically ill subjects with COVID-19 requiring mechanical ventilation. On a subset of the subjects that underwent bronchoscopy, we also quantified SARS-CoV-2 viral load, analyzed the microbiome of the lower airways by metagenome and metatranscriptome analyses and profiled the host immune response. We found that isolation of a hospital-acquired respiratory pathogen was not associated with fatal outcome. However, poor clinical outcome was associated with enrichment of the lower airway microbiota with an oral commensal ( Mycoplasma salivarium ), while high SARS-CoV-2 viral burden, poor anti-SARS-CoV-2 antibody response, together with a unique host transcriptome profile of the lower airways were most predictive of mortality. Collectively, these data support the hypothesis that 1) the extent of viral infectivity drives mortality in severe COVID-19, and therefore 2) clinical management strategies targeting viral replication and host responses to SARS-CoV-2 should be prioritized.

A fundamental, evolutionarily conserved biological mechanism required for long-term memory formation is rapid induction of gene transcription upon learning in relevant brain areas. For episodic types of memories, two regions undergoing this transcription are the dorsal hippocampus (dHC) and prelimbic (PL) cortex. Whether and to what extent these regions regulate similar or distinct transcriptomic profiles upon learning remains to be understood. Here, we used RNA sequencing in the dHC and PL cortex of male rats to profile their transcriptomes in untrained conditions (baseline) and at 1 hour and 6 days after inhibitory avoidance learning. We found that, out of 33,713 transcripts, over 14,000 were significantly expressed at baseline in both regions and approximately 3,000 were selectively enriched in each region. Gene Ontology biological pathway analyses indicated that commonly expressed pathways included synapse organization, regulation of membrane potential, and vesicle localization. The enriched pathways in the dHC were gliogenesis, axon development, and lipid modification, while in the PL cortex included vesicle localization and synaptic vesicle cycle. At 1 hour after learning, 135 transcripts changed significantly in the dHC and 478 in the PL cortex; of these, only 34 were shared. Biological pathways most significantly regulated by learning in the dHC were protein dephosphorylation, glycogen and glucan metabolism, while in the PL cortex were axon development and axonogenesis. The transcriptome profiles returned to baseline by 6 days after training. Thus, a significant portion of dHC and PL cortex transcriptomic profiles is divergent and their regulation upon learning is largely distinct and transient.Significance StatementLong-term episodic memory formation requires gene transcription in several brain regions including the hippocampus and prefrontal cortex. The comprehensive profiles of the dynamic mRNA changes that occur in these regions following learning are not well understood. Here, we performed RNA sequencing in the dorsal hippocampus (dHC) and prelimbic (PL) cortex, a prefrontal cortex subregion, at baseline, 1 hour, and 6 days after episodic learning in rats. We found that at baseline, dHC and PL cortex differentially express a significant portion of mRNAs. Moreover, learning produces a transient regulation of region-specific profiles of mRNA, indicating that unique biological programs in different brain regions underlie memory formation.

OBJECTIVE:<0.05, |log2foldchange| >0.5) and analyzed using weighted gene co-expression network analysis. Weighted gene co-expression network analysis revealed blood modules enriched for immune activation, secretory granules, and coagulation in patients with PAD. Of these 127 differentially expressed transcripts, 40 were significantly associated with MACLE (log-rank false discovery rate <0.1). MicroRNA-4477b was significantly increased in patients with PAD with subsequent MACLE and in a mouse hindlimb ischemia model. CONCLUSIONS:A whole blood transcript signature identified patients with symptomatic PAD and PAD patients at increased risk of MACLE. A previously uncharacterized transcript microRNA-4477b was overexpressed in prevalent PAD, incident MACLE, and in a mouse hindlimb ischemia model. Our novel transcriptomic signature provides insight into potential mechanisms of patients with severe symptomatic PAD.

Encapsulated papillary carcinomas (EPC) of the breast is a unique variant of papillary carcinoma confined to a cystic space with absent or attenuated myoepithelial cell layer. Although staged as an in-situ lesion, it can be associated with invasive ductal carcinoma (IDC). We sought to compare the genomic characteristics of pure EPC and EPC with associated invasive carcinoma (EPCi) at the genomic level. All cases of EPCi harbored recurrent hotspot mutations in PIK3CA. PIK3CA, KMT2A and CREBBP deleterious somatic events were found across both tumor groups, irrespective of invasion status. At the whole transcriptomic level, EPCi cases displayed remarkably similar mRNA profiles when compared to EPC. When EPCi cases were compared with their corresponding IDC, despite significant overlap, we identified differential gene expression in 39 genes with enrichment of multiple pathways including extracellular matrix regulation, cell adhesion and collagen fibril organization. Despite morphologic, genotypic and transcriptomic overlap between pure EPC and EPCi, the latter tumors are likely advanced lesions with PIK3CA activating mutations and enrichment of stromal-related genes implicated in the switch to IDC.

In lung cancer, enrichment of the lower airway microbiota with oral commensals commonly occurs and ex vivo models support that some of these bacteria can trigger host transcriptomic signatures associated with carcinogenesis. Here, we show that this lower airway dysbiotic signature was more prevalent in group IIIB-IV TNM stage lung cancer and is associated with poor prognosis, as shown by decreased survival among subjects with early stage disease (I-IIIA) and worse tumor progression as measured by RECIST scores among subjects with IIIB-IV stage disease. In addition, this lower airway microbiota signature was associated with upregulation of IL-17, PI3K, MAPK and ERK pathways in airway transcriptome, and we identified Veillonella parvula as the most abundant taxon driving this association. In a KP lung cancer model, lower airway dysbiosis with V. parvula led to decreased survival, increased tumor burden, IL-17 inflammatory phenotype and activation of checkpoint inhibitor markers.